Magnetic starter



Dec, 27, 1927.

O. BRISBOIS mmmxc 512mm Filled. Oct. 8, 1925' 2 Sheets-Sheet 2 Paten edDec. 27, 1927.

1,653,617 UNIT'EDISTATES, PATENT OFFICE.

om oN Brussels, 01" CHICAGO, ILLINoIs.

MAGNETIC sran'rnn.

Application filed October 8, 1928. Serial No. 367,103.

This invention relates to a magnetic engine starter of that type inwhich the magnetic flux is utilized for shifting a displaced armaturefor bringing a driving member,

5 such as a pinion, ,into engagement with a driven member, such as agear, upon the engine shaft.

Starting motors of this type have not been generally successful onaccount of their In high rate of speed at the time that the drivingmember is brought into meshing relation with the driven member. Manyattempts have been made to decrease the speed of rotation during theperiod of engagement of the driving and driven member. Resistance coilshave been used, and while they have met with some-success, the cost'ofsuch coils is prohibitive. It has also been proposed to vary the angularrelation of the brushes from their normal position, but for variousreasons this scheme has hitherto been unsuccessful on account of theexcessive sparking, short circuiting effects that would be made in the 72a the relative shifting of the brushes and commutators. While it seemsunnecessary -to discuss all the other schemes that have ben attempted,it might be said that at the pres ent t1me,no one has perfected apractical 3 and commercial magnetic starter that has met therequirements of the automobile manufacturer. The few that are inuse,einploy expensive resistance coils or systems, that are prohibitiveexcept in the very high priced cars. 1 i F This invention is designed toovercome the above noted objections and aims to provide a practical andcommercially successful magnetic starter, [that is inexpensive and 40that can be used on any ordinary car. In

attaining these results, there hasbeen provided a magnetic starter inwhich the com-. mutator brushes are initially angularly displaced fordecreasing'the meshing speed of the motor and in which the arrangementis such that a mechanical retardation or drag is effecteduto also lowerthe speed of rotation, in which the brushes travel longitudi- .nallywith the move ents of the armature,

.in which the strong armature-displacing spring has been eliminated sothat the total endwise torque is eifectiveto shift the armature, and. inwhich the movements of the armature are controlled man-automatic waythrough the operationv of the motor. 'With and the grooves commutator bythese and other advantages in view which will become more apparent inthe following description anddisclosures, this invention comprlses thenovel mechanism and combi-' nations hereinafter described and moreparticularly pointed out and defined in the appended claims.

In the accompanying drawings which illustrate certain preferredembodiments of this invention andin which. similar reference numeralsrefer to similar features in, the different views:

On the drawings:

Figure 10 is an elevational view of the starting motor. V Figure 2 is anenlarged longitudinal section of the same showing parts in elevation,illustrating an end commutator.

Figure 3 is a front elevational view of the commutator brushes andsupporting ring with the motor shaft and easing shown in section. I v

Figure 4 is'an enlarged part sectional and elevational view of thestarting-motor.

Figure 5 is an enlarged fragmentary sec: tional view of the motor casingillustrating certain features of the invention.

Figure 6 is a front elevational view of the starting motor.

Figure 7 is an enlarged longitudinal section through a starting motorinvolving a modification of the invention. I

Figure 8 is a front elevational view of the brush ring showing, parts insection and involving the modified form of the invention. Y I

As shown on the drawings:

. In referring to the drawing, especially to Figures 1 to 6, there isillustrated a motor compri'sing the supporting casing 1 having aforwardextended bea'ring 2 in which a shaft 3 is slidably mounted. A drivingmember 4 in the form of a small seven toothed pinion is secured uponthis shaft. The armature 5 is supported upon a shaft 6 journalled in.the extended bearings and connectedto the "shaft 3. The rear end of theshaft 6'is reduced and slidably supported in a sufiiciently longbearingsocket -7 in the central part of the rear end of the motor 0 sing. s

In the,first form of the i vention, the armature! 5- provided with arearend commutator 18 against which a plurality of brushes 9 bear. p I vI supported in. suitable holders .110 and 1 These brushes areslidably'of the inner periphery of the casing. The

holder 10 has a central hub 13 which is frictionally held upon the motorshaft between a collar 14 and a washer 15 abutting the end commutator.The outer ends of the brush holder 10,are welded or secured to the ring12. The brush holders 11' have up per attaching brackets that are weldedor secured to the ring 12. It is therefore obvious that shifting orrotating of the ring 12 will carry the brush holders and brushestherewith. Springs 16 secured upon the brush holders yieldingly urge thebrushes against thd commutator.

A stud 17 (Figure 5) having a head 21 is secured in the ring 12, and aroller 17 is mounted upon said stud. This stud projects into an arcuateor curved slot 18 in the motor casing. The contour of this slot is bestshown in Figure 4: and it will be noted that it extends rearwardly fromits mostforward point and curves or extends in a direction opposite tothe normal starting rotation of the armature as indicated by the arrowin said figure. Consequently as the motor is started and the armature isdrawn inwardly, the stud 17 is constrained to follow the curved guideway in a direction opposite to the direction of rotation of thearmature. In the position shown in Figure 4, the ring 12 is in such aposition that the brushes are angularly displaced with respect to theirnormal operating position so that when the motor circuit is closed, themagnetic field produced by the armature WlIlClings is displaced an amoutcorresponding substantially to the angular displacement of the brushes.The result is that the magnetic force produced by the armature coils andwhich reacts upon the field flux to produce rotation of the. armature,tends to rotate the armature in both directions, with slightly unequaland opposite forces, the difference being sufficient to impart a slightrotation to the armature for meshing puroses. The magnetic flux howeverwill longitudinally sliift the armature inwardly, causing the stud 17 totravel in the slot to gradually advancethe brush holding ring 12 tonormal operating position. While this ad vancing movement of the brusheswill tend I to increase the rotation of the armature, it

will be appreciated that the opposite direction of rotation of thebrushes caused by the stud 17 traveling in such opposite direction inthe slot 18, will effect a braking action, retardation or drag upon therotation of the armature. As the rotational "torque of the motor is notvery great during such movement of the brushes, it will be appreciatedthat such a brakingaction may be appreciably effective in reducing themeshing speed of'the' armature. In order to retain the stud 17 in eitherend of the slot, some yielding means should be provided. In the presentexemplification of this invention I have illustrated a double endedyielding detent member 1.9 (Figure 5) which is adapted to be secured soas to overlie the curved or spiral slot 18. Adjacent each end of saidmember, there is a downwardly projecting hump or shoulder 20 that liesin the path of movement of the head 21 of the stud 17, and which willyield upwardly allowing the stud to pass during the operation of themotor, very little effort being required to cause a yielding of thedetent. These shoulders are spaced a suitable distance from the ends ofthe slot to confine the stud.

In Figure 7, there is shown a starting motor similar to the one justdescribed except that it has radially extending brushes and the usualcylindrical commutator. In referring to said drawing, it will beobserved that a ring 12 extends circumferentially of the inner peripheryof the motor casing, this ring is provided with a stud 17 extendingthrough a spiral slot 18 in the motor casing as shown in Figure 5. Thering 12 is integral with an apertured disk or spider 22 having a hub 23which is frictionally confined on the shaft 6 between the collar 24 andthe collar 25 adjacent the cylindrical commutator 26 on the motor shaft.A plurality of brush holders 27, four in the present instance, extendlaterally from the disk. Brushes 28 are slidably mounted in theseholders and-are yieldingly urged into contact with the commutator 26through the springs 29 which are secured to' the ring 12". lVhile theoperation of the starting motor can be clearly understood from theforegoing, a brief description will be given for the purpose ofexplaining the demeshing of the motor pinion and engine gear, and thecontrol of the armature. hen the motor circuit is closed, the brushesare angularly displaced with respect to their normal operatingpositionand the armature is longitudinally displaced with respect to its field.The magnetic flux will draw the armature inwardly since the same isdesigned to be displaced forwardly of its field. As the armature isdrawn inwardly, it will rotate slightly' in the direction of tliearrowsshown in Figures 5 and 6, and the stud 17 will be caused to travelrearwardly in the slot 18 in an opposite direction carrying the brushestherewith so that a drag or braking effect will be imparted to thearmature shaft. lVhen the stud 17 reaches the opposite or rear end ofthe slot as viewed in Figure 4, the brushes will be in their normaloperating position and the pinion 4 will have been brought into meshwith the usual engine gear for starting the engine, As soon as theengine has been started, and the motor circuit tate the armature,'andcause the stud 17 to travel forwardly in the slot to thereby shift thearmature forwardly and demesli the pinionfrom the engine gear. vThismove- -ment is made possible-by the fact that the friction between thebrushes and commutator is sufiicient to cause the brushes to rotate withthe commutator on the armature and to overcome the opposed action of thestud in the cam slot.

From the foregoing, it will be apparentthe motor. It will also beappreciated that the elimination of the armature displacing spring thathas usually been heretofore used affords a greater endwise torque forlongi tudinally shifting the armature for bringing the gears intomeshing relation, andthat the armature is automatically restored,thereby demeshing' the gears and the brushes are automatically displacedthrough the action imparted by the arcuat slot upon the brush holdingring afterthe motor circuit is closed. i

Iv am aware that many changes may be made and numerous details ofconstruction may be varied through a wide range without departing fromthe principles of this invention, and I therefore do not purposelimiting the patent granted hereon. otherwise than necessitated by theprior art.

I I claim as my invention:

. 1. An engine starter comprising a motor having av normally displacedand shiftable armature, a commutator in connection with said armature,normally displaced brushes in contact with said commutator and shiftabletherewith, and means for automatically rotating'said brushes relative tothe armature during the shifting of the latter in one direction. i

2. The combination with an'electric start- I -ing lIlOtOIhfLVlIlg alongitudinally shiftable means armature and angularly shiftable commutamtor brushes, of means for automatically shifting said brushes during thelongitudinal :movement of said armature'in a reverse directlon to. thenormal rotation of said arma- H ture. s I

3. In an engine starter of the class described the combination wiwnelectric mo- .tor having a longitudinall s iftable armature andangularly .shiftab ecommutator brushes movable with said armature, of

for automatically rotating said 7 brushes during ,theshifting movementof said armature when the motor is energized,

and longitudinally shifting said brushes with said armature when themotor is deenergized and mechanically rotated.

4. The combination with an engine member, of a starter thereforcomprising an electric motor having a longitudinally shiftable armatureadapted for operative connection with said engine member, said armaturehaving rotatable commutator brushes, supported for shifting movementtherewith, and mechanism for causing said brushes to rotate inadirection opposite to the rotation of the armature upon energizationofthe motor for the purpose set forth.

5. The combination with an engine member, of a starter thereforcomprising a motor ber, of a starter thereforcomprising a mo-' torhaving a longitudinally shiftable armature havin means adapted to bebrought into operative relation with said engine member, rotatable andshiftable commutator brushes for said armature, a holder for saidbrushes, and means havinga guide way receiving a part of said holder forcontrolling the rotation and shifting movements of said holder duringthe operation of said motor. 7. The combination with an engine member,of a starter therefor comprising a mo tor having a longitudinallyshiftable armature provided with means adapted to be brought intooperative relation with said engine member, a rotatable andlongitudinally shiftable brush holder in connection with said armatureautomatically movable upon excitation of said motor and shiftablelongitudinally upon de-energization of the motor for-shifting saidarmature and disconnect ing said means from the engine member.

8. The combinationwith an engine member, of a starter thereforcomprising a motor having a longitudinally shift-able armature providedwith means for engaging said engine member, a rotatable andlongitudinally shiftable brush holder having a stud, means in connectionwith said motor providing a able for shifting said armature anddisconnecting said means upon de-energization of the motor.

9. In an engine startlng motor, a longitudinally shiftable armature, arotatable and longitudinally shiftabl'e commutator brush holder, meansfor automatically rotating said holder relative to the armature andlongitudinally shifting the same with said armature when said motor isenergized for start-" ing said engine, said means operating to shiftsaid holder and armature to inoperative position when the motor is(lo-energized and driven by said engine.

10. The combinat1on with an engine member, of a starter thereforcomprising a motor havin a lon itudinal] shiftable armature :1 o y .ginemember, said holder being shifted longitudinally for shifting saidarmature when the motor is de-energized and its armature rotated by saidengine member.

11. In an engine starting motor, a lon-- gitudinall y shiftablearmature, a commutator brush holder mounted for rotation andlongitudinal movement, means engageable with said holder for controllingits movements, whereby said holder will shift with said armature androtate relatively thereto in an opposite direction when said armaturemoves in one direction, and will shift and rotate with said armaturewhen the same is shifted in the other direction for the purposedescribed.

12. In a starter for an engine, a motor adapted to drive said engine,said motor having a shiftable armature normally displaced, and having acommutator brush holder mounted for predetermined rotation relative tosaid armature, and means actuated by the shifting of said arn'iature forrotating said brush holder for the purpose described.

In testimony whereof I have hereunto4 subscribed my name.

ODILON BRISBOIS.

